The incorporation of electronic devices with pneumatic tire structures yields many practical advantages. Tire electronics may include sensors and other components for relaying tire identification parameters and also for obtaining information regarding various physical parameters of a tire, such as temperature, pressure, number of tire revolutions, vehicle speed, etc. Such performance information may become useful in tire monitoring and warning systems, and may even potentially be employed with feedback systems to regulate proper tire pressure levels.
U.S. Pat. No. 5,749,984 (Frey et al.) discloses a tire monitoring system and method that is capable of determining such information as tire deflection, tire speed, and number of tire revolutions. Another example of a tire electronics system can be found in U.S. Pat. No. 4,510,484 (Snyder), which concerns an abnormal tire condition warning system. U.S. Pat. No. 4,869,486 (Wing et al.) also relates to tire electronics, and more particularly discloses an exemplary revolution counter for use in conjunction with automotive and truck tires. Examples of aspects of tire pressure monitoring systems are disclosed in U.S. Pat. Nos. 4,004,271 (Haven et al.), U.S. Pat. No. 4,742,857 (Gandhi), U.S. Pat. No. 5,616,196 (Loewe), and U.S. Pat. No. 5,928,444 (Loewe et al.).
Yet another potential capability offered by electronics systems integrated with tire structures corresponds to asset tracking and performance characterization for commercial vehicular applications. Commercial truck fleets, aviation crafts and earthmover/mining vehicles are all viable industries that could utilize the benefits of tire electronic systems and related information transmission. Tire sensors can determine the distance each tire in a vehicle has traveled and thus aid in maintenance planning for such commercial systems. Vehicle location and performance can be optimized for more expensive applications such as those concerning equipment. Entire fleets of vehicles could be tracked using RF tag transmission, exemplary aspects of which are disclosed in U.S. Pat. No. 5,457,447 (Ghaem et al.).
Since electronics assemblies within a tire typically relay information in a wireless fashion, such assemblies must often include a radio frequency (RF) device outfitted with one or more antennas. An example of an antenna for use with transponder type devices in a tire monitoring environment is disclosed in U.S. Pat. No. 5,196,845 (Myatt.) The frequency at which such RF device preferably operates (and the corresponding frequency at which the antenna preferably resonates) varies depending on geographic location. This is due in part to the fact that RF regulations and standards are not globally homogeneous. Authorized operational frequencies, duty cycles, power levels, etc. of an RF device often differ among continents and/or countries. As such, it may be desirable for a single electronics assembly and corresponding antenna to effectively transmit and receive RF signal information at multiple frequencies of interest.
Other design features besides electrical performance characteristics may be of importance to electronics assemblies and antennas used specifically in a tire environment. Such components are provided relative to a location that is constantly moving and flexing, thus subjecting the components to excessive heat as well as tension and other dynamic forces. Such forces may yield a potential for damaging the electronics assemblies and associated antenna structure. A particular example of such undesirable damage corresponds to an antenna being separated from its associated electronic assembly and/or RF device. As such, electronic devices and corresponding antenna structures for use within a tire may be designed with practicality and mechanical robustness in mind.
The disclosures of all of the foregoing United States patents are hereby fully incorporated into this application for all purposes by reference thereto. While various tire electronics systems and antenna structures therefor have been developed, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the subject technology.